Integrated circuits are widely used in electronic devices of many types. Conventional aluminum (Al) and Al alloys have been widely used as interconnection materials for integrated circuits. However, the downscaling of metal interconnect lines and the increased electrical current density will result in greater RC time delay along with enhanced electromigration (EM) and stress-induced void failures.
The article entitled “Advanced Metal Barrier Free Cu Damascene Interconnects with PECVD Silicon Carbide Barriers for 90/65 nm BEOL Technology”, IEDM 2002, Wu et al., pages 595 to 598, describes the use of SiC to replace the barrier metal layer to achieved improved ET results and a lower dielectric constant (k) in copper (Cu)/low-k technology.
U.S. Pat. No. 6,541,842 B2 to Meynen et al. describes an integrated circuit wherein a sealing dielectric layer is applied between a porous dielectric layer and a metal diffusion barrier layer. The sealing dielectric layer closes the pores on the surface and sidewalls of the porous dielectric layer. The sealing dielectric layer is a CVD deposited film having the composition SixCyHz.
U.S. Patent Application Publication No. US 2002/0027286 A1 to Sundararajan et el. describes a method of forming a semiconductor device (and the device so formed) by forming a metal portion over underlying portions; depositing a single layer of silicon carbon nitride (SiCN) layer over the metal portion; and depositing a dielectric layer over the SiCN layer.
U.S. Pat. Nos. 6,140,220 and 6,348,733 B1 to Lin each describe dual damascene process and structure with dielectric barrier layer.
U.S. Pat. No. 6,444,568 B1 to Sundararajan et el. describes a method of forming a copper diffusion barrier.
UK Patent Application No. GB 2 365 215 A to McGahay et al. describes a method of forming a semiconductor device (and the device so formed) by forming a composite diffusion barrier between a copper structure and an insulating layer wherein the composite diffusion barrier comprises a layer of dense material and a film of material capable of forming a protective oxide in a self-limiting manner in the presence of oxygen or water.